diff options
Diffstat (limited to 'nbd-client.c')
| -rw-r--r-- | nbd-client.c | 358 |
1 files changed, 358 insertions, 0 deletions
diff --git a/nbd-client.c b/nbd-client.c new file mode 100644 index 0000000..4df2281 --- /dev/null +++ b/nbd-client.c @@ -0,0 +1,358 @@ +/* + * Open connection for network block device + * + * Copyright 1997,1998 Pavel Machek, distribute under GPL + * <pavel@atrey.karlin.mff.cuni.cz> + * + * Version 1.0 - 64bit issues should be fixed, now + * Version 1.1 - added bs (blocksize) option (Alexey Guzeev, aga@permonline.ru) + * Version 1.2 - I added new option '-d' to send the disconnect request + * Version 2.0 - Version synchronised with server + * Version 2.1 - Check for disconnection before INIT_PASSWD is received + * to make errormsg a bit more helpful in case the server can't + * open the exported file. + */ + +#include "config.h" +#include "lfs.h" + +#include <sys/ioctl.h> +#include <sys/socket.h> +#include <sys/types.h> +#include <unistd.h> +#include <netinet/tcp.h> +#include <netinet/in.h> /* sockaddr_in, htons, in_addr */ +#include <netdb.h> /* hostent, gethostby*, getservby* */ +#include <stdio.h> +#include <fcntl.h> +#include <syslog.h> +#include <stdlib.h> +#include <sys/mount.h> +#include <errno.h> + +#ifndef __GNUC__ +#error I need GCC to work +#endif + +#include <linux/ioctl.h> +#define MY_NAME "nbd_client" +#include "cliserv.h" + +int check_conn(char* devname, int do_print) { + char buf[256]; + int fd; + int len; + if(!strncmp(devname, "/dev/", 5)) { + devname+=5; + } + snprintf(buf, 256, "/sys/block/%s/pid", devname); + if((fd=open(buf, O_RDONLY))<0) { + if(errno==ENOENT) { + return 1; + } else { + return 2; + } + } + len=read(fd, buf, 256); + buf[len-1]='\0'; + if(do_print) printf("%s\n", buf); + return 0; +} + +int opennet(char *name, int port, int sdp) { + int sock; + struct sockaddr_in xaddrin; + int xaddrinlen = sizeof(xaddrin); + struct hostent *hostn; + int af; + + hostn = gethostbyname(name); + if (!hostn) + err("Gethostname failed: %h\n"); + + af = AF_INET; + if(sdp) { +#ifdef WITH_SDP + af = AF_INET_SDP; +#else + err("Can't do SDP: I was not compiled with SDP support!"); +#endif + } + if ((sock = socket(af, SOCK_STREAM, IPPROTO_TCP)) < 0) + err("Socket failed: %m"); + + xaddrin.sin_family = af; + xaddrin.sin_port = htons(port); + xaddrin.sin_addr.s_addr = *((int *) hostn->h_addr); + if ((connect(sock, (struct sockaddr *) &xaddrin, xaddrinlen) < 0)) + err("Connect: %m"); + + setmysockopt(sock); + return sock; +} + +void negotiate(int sock, u64 *rsize64, u32 *flags) { + u64 magic, size64; + char buf[256] = "\0\0\0\0\0\0\0\0\0"; + + printf("Negotiation: "); + if (read(sock, buf, 8) < 0) + err("Failed/1: %m"); + if (strlen(buf)==0) + err("Server closed connection"); + if (strcmp(buf, INIT_PASSWD)) + err("INIT_PASSWD bad"); + printf("."); + if (read(sock, &magic, sizeof(magic)) < 0) + err("Failed/2: %m"); + magic = ntohll(magic); + if (magic != cliserv_magic) + err("Not enough cliserv_magic"); + printf("."); + + if (read(sock, &size64, sizeof(size64)) < 0) + err("Failed/3: %m\n"); + size64 = ntohll(size64); + +#ifdef NBD_SET_SIZE_BLOCKS + if ((size64>>10) > (~0UL >> 1)) { + printf("size = %luMB", (unsigned long)(size64>>20)); + err("Exported device is too big for me. Get 64-bit machine :-(\n"); + } else + printf("size = %luKB", (unsigned long)(size64>>10)); +#else + if (size64 > (~0UL >> 1)) { + printf("size = %luKB", (unsigned long)(size64>>10)); + err("Exported device is too big. Get 64-bit machine or newer kernel :-(\n"); + } else + printf("size = %lu", (unsigned long)(size64)); +#endif + + if (read(sock, flags, sizeof(*flags)) < 0) + err("Failed/4: %m\n"); + *flags = ntohl(*flags); + + if (read(sock, &buf, 124) < 0) + err("Failed/5: %m\n"); + printf("\n"); + + *rsize64 = size64; +} + +void setsizes(int nbd, u64 size64, int blocksize, u32 flags) { + unsigned long size; + int read_only = (flags & NBD_FLAG_READ_ONLY) ? 1 : 0; + +#ifdef NBD_SET_SIZE_BLOCKS + if (size64/blocksize > (~0UL >> 1)) + err("Device too large.\n"); + else { + int er; + if (ioctl(nbd, NBD_SET_BLKSIZE, (unsigned long)blocksize) < 0) + err("Ioctl/1.1a failed: %m\n"); + size = (unsigned long)(size64/blocksize); + if ((er = ioctl(nbd, NBD_SET_SIZE_BLOCKS, size)) < 0) + err("Ioctl/1.1b failed: %m\n"); + fprintf(stderr, "bs=%d, sz=%lu\n", blocksize, size); + } +#else + if (size64 > (~0UL >> 1)) { + err("Device too large.\n"); + } else { + size = (unsigned long)size64; + if (ioctl(nbd, NBD_SET_SIZE, size) < 0) + err("Ioctl NBD_SET_SIZE failed: %m\n"); + } +#endif + + ioctl(nbd, NBD_CLEAR_SOCK); + + if (ioctl(nbd, BLKROSET, (unsigned long) &read_only) < 0) + err("Unable to set read-only attribute for device"); +} + +void set_timeout(int nbd, int timeout) { +#ifdef NBD_SET_TIMEOUT + if (timeout) { + if (ioctl(nbd, NBD_SET_TIMEOUT, (unsigned long)timeout) < 0) + err("Ioctl NBD_SET_TIMEOUT failed: %m\n"); + fprintf(stderr, "timeout=%d\n", timeout); + } +#endif +} + +void finish_sock(int sock, int nbd, int swap) { + if (ioctl(nbd, NBD_SET_SOCK, sock) < 0) + err("Ioctl NBD_SET_SOCK failed: %m\n"); + +#ifndef SO_SWAPPING + if (swap) + err("You have to compile me on machine with swapping patch enabled in order to use it later."); +#else + if (swap) + if (setsockopt(sock, SOL_SOCKET, SO_SWAPPING, &one, sizeof(int)) < 0) + err("Could not enable swapping: %m"); +#endif +} + +int main(int argc, char *argv[]) { + int port, sock, nbd; + int blocksize=1024; + char *hostname, *nbddev; + int swap=0; + int cont=0; + int timeout=0; + int sdp=0; + u64 size64; + u32 flags; + + logging(); + + if (argc < 3) { + errmsg: + fprintf(stderr, "nbd-client version %s\n", PACKAGE_VERSION); + fprintf(stderr, "Usage: nbd-client [bs=blocksize] [timeout=sec] host port nbd_device [-swap] [-persist]\n"); + fprintf(stderr, "Or : nbd-client -d nbd_device\n"); + fprintf(stderr, "Or : nbd-client -c nbd_device\n"); + fprintf(stderr, "Default value for blocksize is 1024 (recommended for ethernet)\n"); + fprintf(stderr, "Allowed values for blocksize are 512,1024,2048,4096\n"); /* will be checked in kernel :) */ + fprintf(stderr, "Note, that kernel 2.4.2 and older ones do not work correctly with\n"); + fprintf(stderr, "blocksizes other than 1024 without patches\n"); + return 1; + } + + ++argv; --argc; /* skip programname */ + + if (strcmp(argv[0], "-d")==0) { + nbd = open(argv[1], O_RDWR); + if (nbd < 0) + err("Can not open NBD: %m"); + printf("Disconnecting: que, "); + if (ioctl(nbd, NBD_CLEAR_QUE)< 0) + err("Ioctl failed: %m\n"); + printf("disconnect, "); +#ifdef NBD_DISCONNECT + if (ioctl(nbd, NBD_DISCONNECT)<0) + err("Ioctl failed: %m\n"); + printf("sock, "); +#else + fprintf(stderr, "Can't disconnect: I was not compiled with disconnect support!\n" ); + exit(1); +#endif + if (ioctl(nbd, NBD_CLEAR_SOCK)<0) + err("Ioctl failed: %m\n"); + printf("done\n"); + return 0; + } + if(strcmp(argv[0], "-c")==0) { + return check_conn(argv[1], 1); + } + + if (strncmp(argv[0], "bs=", 3)==0) { + blocksize=atoi(argv[0]+3); + ++argv; --argc; /* skip blocksize */ + } + + if (strncmp(argv[0], "timeout=", 8)==0) { + timeout=atoi(argv[0]+8); + ++argv; --argc; /* skip timeout */ + } + + if (argc==0) goto errmsg; + hostname=argv[0]; + ++argv; --argc; /* skip hostname */ + + if (argc==0) goto errmsg; + port = atoi(argv[0]); + ++argv; --argc; /* skip port */ + + if (argc==0) goto errmsg; + nbddev = argv[0]; + nbd = open(nbddev, O_RDWR); + if (nbd < 0) + err("Can not open NBD: %m"); + ++argv; --argc; /* skip device */ + + if (argc>3) goto errmsg; + if (argc) { + if(strncmp(argv[0], "-swap", 5)==0) { + swap=1; + ++argv;--argc; + } + } + if (argc) { + if(strncmp(argv[0], "-persist", 8)==0) { + cont=1; + ++argv;--argc; + } + } + if (argc) { + if(strncmp(argv[0], "-sdp", 4)==0) { + sdp=1; + ++argv;--argc; + } + } + if(argc) goto errmsg; + sock = opennet(hostname, port, sdp); + argv=NULL; argc=0; /* don't use it later suddenly */ + + negotiate(sock, &size64, &flags); + setsizes(nbd, size64, blocksize, flags); + set_timeout(nbd, timeout); + finish_sock(sock, nbd, swap); + + /* Go daemon */ + + chdir("/"); + do { +#ifndef NOFORK + if (fork()) { + while(check_conn(nbddev, 0)) { + sleep(1); + } + open(nbddev, O_RDONLY); + exit(0); + } +#endif + + if (ioctl(nbd, NBD_DO_IT) < 0) { + fprintf(stderr, "Kernel call returned: %m"); + if(errno==EBADR) { + /* The user probably did 'nbd-client -d' on us. + * quit */ + cont=0; + } else { + if(cont) { + u64 new_size; + u32 new_flags; + + fprintf(stderr, " Reconnecting\n"); + close(sock); close(nbd); + sock = opennet(hostname, port, sdp); + nbd = open(nbddev, O_RDWR); + negotiate(sock, &new_size, &new_flags); + if (size64 != new_size) { + err("Size of the device changed. Bye"); + } + setsizes(nbd, size64, blocksize, + new_flags); + + set_timeout(nbd, timeout); + finish_sock(sock,nbd,swap); + } + } + } else { + /* We're on 2.4. It's not clearly defined what exactly + * happened at this point. Probably best to quit, now + */ + fprintf(stderr, "Kernel call returned."); + cont=0; + } + } while(cont); + printf("Closing: que, "); + ioctl(nbd, NBD_CLEAR_QUE); + printf("sock, "); + ioctl(nbd, NBD_CLEAR_SOCK); + printf("done\n"); + return 0; +} |